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1.
Swai ES Karimuribo ED French NP Fitzpatrick JL Bryant MJ Kambarage DM Ogden NH 《Journal of the South African Veterinary Association》2007,78(1):15-20
Variations in the seroprevalence of antibody to Babesia bigemina infection by farm and animal level risk factors were investigated for 2 contrasting regions of Tanga and Iringa in Tanzania. Tanga is situated in the eastern part of the country and has typical tropical coast climate while Iringa is situated in the Southern Highlands and has a tropical highland climate. Two hundred farms from each region were selected using simple random sampling procedure and visited once between January 1999 and April 1999. Blood samples were collected from 1329 smallholder dairy animals on selected farms for harvesting serum which was subsequently used for serodiagnosis of B. bigemina using an indirect enzyme linked immuno-sorbent assay (ELISA). Of the 1329 sera samples screened, 34.9 % were positive for B. bigemina. The prevalence was higher in Iringa Region [43%, 95% confidence intervals (CI) = 39.5-47.3] than in Tanga Region (27%, CI = 23.6-30.5). Using a logistic binomial regression model as an analytical method for predicting the likelihood of animal seropositivity, we found (in both regions) that the risk of positive reaction varied with the animal's age, history of grazing and geographical location. Seroprevalence increased with age (beta = 0.01 and 0.01 per year of age, P < 0.005 in Tanga and Iringa, respectively). Animals located in Lushoto and Iringa urban district were associated with increased risk of seropositivity [Odds ratio (OR) = 4.24, P = 0.001, for Lushoto, and OR = 1.81, P = 0.040, for Iringa Urban, respectively). Animals grazed 3 months prior to sampling had higher odds for seropositivity than zero/semi-grazed, despite farmer-reported high frequency of tick control (OR = 2.71, P = 0.0087, for Tanga, and OR = 4.53, P = 0.001, for Iringa). Our study suggests that even though herd sizes are small, B. bigemina infection is widespread in many smallholder dairy farms and endemic stability with respect to this disease has not yet been attained, but the observed levels are sufficiently high to ensure that clinical disease would be a risk. 相似文献
2.
RR Moura ES Lopes‐Junior DIA Teixeira IA Serova LE Andreeva LM Melo VJF Freitas 《Reproduction in domestic animals》2010,45(5):e101-e106
The objective of this study was to examine the effect of donor breed on pronuclear‐stage embryo yield to be used for DNA microinjection in a transgenesis goat program. Twelve Canindé and twelve Saanen goats were heat synchronized using a progestagen‐cloprostenol treatment. Forty‐eight hours before the sponge removal, superovulation was induced with a total administration of 4.4 mg/kg bodyweight NIH‐FSH‐P1, given twice daily in decreasing doses over 3 days. In addition, goats received 100 μg of GnRH and they were hand‐mated at 36 and 48 h after progestagen removal. Embryo recovery was performed by oviduct flushing at 72 h after sponge removal. Embryos were microinjected with a DNA construct and noticeable swelling of the nuclei was the criterion for successful microinjection. The total diameter, cytoplasm diameter, zona pellucida thickness and pronuclei diameter were measured for each microinjected embryo. A higher (p < 0.05) percentage of fertilized ova was observed in Canindé (89.9%) than Saanen (36.2%) goats. In addition, Canindé donors produced a higher percentage of pronuclear embryos when compared with Saanen: 72.5% vs 20.6% (p < 0.05), respectively. Successful microinjection was verified in 96.7% and 73.3% of times in Canindé and Saanen embryos, respectively (p < 0.05). Significant differences were observed for all morphometric parameters except for cytoplasm diameter. In conclusion, under our study experimental conditions, Canindé were more efficient than Saanen goats concerning the pronuclear embryo yield and manipulation. The use of Canindé goats in transgenesis programs could be increase the interest in their breeding and could be contribute to saving them from extinction. 相似文献
3.
Ogden NH Gwakisa P Swai E French NP Fitzpatrick J Kambarage D Bryant M 《Veterinary parasitology》2003,112(3):177-183
The ability of PCR to detect infections of Theileria parva, the cause of East Coast Fever, in field-collected tick and bovine samples from Tanzania was evaluated. PCR-detected infection prevalence was high (15/20, 75%) in unfed adult Rhipicephalus appendiculatus ticks that fed as nymphs on an acutely-infected calf, but low (22/836, 2.6%) in unfed adult R. appendiculatus collected from field sites in Tanzania. Tick infection prevalence was comparable to that in previous studies that used salivary gland staining to detect T. parva infection in field-collected host-seeking ticks. Of 282 naturally-exposed zebu calves, seven had PCR-positive buffy coat samples prior to detection of Theileria spp. parasites in stained buffy coat cells or lymph node biopsies. Evidence of Theileria spp. infections was detected in stained smears of lymph node biopsies from 109 calves (38.6%) and buffy coat samples from 81 (28.7%), while buffy coat samples from 66 (23.4%) were PCR-positive for T. parva. Implications of these findings for the sensitivity and specificity of the PCR are discussed. 相似文献
4.
A. M. PIRES M. F. MAGALHÃES L. MOREIRA DA COSTA M. J. ALVES & M. M. COELHO 《Fisheries Management and Ecology》2008,15(1):49-58
Abstract The effects of an extreme flash flood on the native fish assemblages across a Mediterranean catchment in Southwest Portugal were investigated. The fish community structure and habitat were surveyed at 10 sites pre- and post-flood. Overall species richness and rank abundances changed little after the flood, despite there being a consistent decline in the abundance of small cyprinids. Pre- and post-flood habitat correlates of abundance changed for at least some species, and variability in assemblage structure was associated with flood, depth and pH. These results indicate that extreme floods occurring early in the wet season may have little disruptive effects on the overall structure of native fish assemblages in Mediterranean streams, although may at least partially influence population dynamics for some species. Habitat quality and complexity are likely to play a role in mediating species responses to flooding. 相似文献
5.
Swai ES Bryant MJ Karimuribo ED French NP Ogden NH Fitzpatrick JL Kambarage DM 《Tropical animal health and production》2005,37(6):513-525
A retrospective cross-sectional study was conducted on 200 randomly selected smallholder farms from a mixed dairy farming
system in Tanga, Tanzania, between January and April 1999. We estimated the frequency and determinants of long calving interval
(LCI), retention of fetal membrane (RFM), dystocia, and abortion in smallholder crossbred cattle and explored birth trends.
The mean calving interval was 500 days and birth rate was 65 per 100 cow-years. Dystocia was reported to affect 58% of calvings,
and 17.2% of animals suffered RFM. Using mixed effect models, the variables associated with LCI, RFM and dystocia were breed,
level of exotic blood and condition score. Zebu breeding was associated with LCI (odds ratio (OR) = 2.3, p = 0.041) and Friesian breeding with lower odds for RF (OR = 0.26, p = 0.020). Animals with higher levels of exotic blood had lower odds for evidence of dystocia (OR = 0.45, p =0.021). Evidence of dystocia was significantly associated with poor condition score (P = −1.10, p = 0.001). Our observations suggest that LCIs are common in smallholder dairy farms in this region and a likely source of
economic loss. Dystocia, RFM, poor condition score and mineral deficiency were common problems and were possibly linked to
LCI. 相似文献
6.
Emmanuel Senyael Swai Jackson Eliona Kaaya 《Tropical animal health and production》2012,45(1):211-217
Food-borne parasitic diseases, such as toxoplasmosis, are increasingly becoming a global food safety concern. A cross-sectional study was conducted to investigate seroprevalence and risk factors of Toxoplasma gondii seropositivity in apparently healthy, unvaccinated dairy goat flocks reared under mixed smallholders, northern Tanzania between April and October 2011. Flock- and animal-level data were collected using a questionnaire. Sera (n?=?337) collected from goats aged ≥6 months and from 102 flocks, respectively, were analyzed using modified Eiken latex agglutination test. A flock was classified as T. gondii seropositive if at least one animal tested positive. Titers considered diagnostically significant (≥1:16) were detected in 19.3 % of goats and 45.17 % of flocks, respectively. The antibody levels ranged from 1:16 to 1:2,048 and among the seropositive goats, the proportion of high antibody levels (≥1:2,048), suggestive of acute infection, was 1.5 %. The study revealed that goats raised in Babati are at a lower risk of acquiring T. gondii infection (P?=?0.00209) than those which are raised in Arumeru district. The prevalence of T. gondii antibody was significantly higher in crossbred (24.7 %) and Saanen (24.4 %) breed goats than in local (14.3 %) and Toggenburg (12.1 %) and in females than in males (P?=?0.043). No significant difference was observed among goats kept under various husbandry practices. The relatively high seroprevalence detected in this study suggests that toxoplasmosis may be posing a significant animal and human health risk and that the consumption of goat meat may play a role in the transmission of the disease to humans. 相似文献
7.
Swai ES Mtui PF Chang'a AK Machange GE 《Journal of the South African Veterinary Association》2008,79(2):71-75
Serum samples collected in a cross-sectional survey of grazing cattle on Manyara Ranch, Monduli district, Tanzania, were tested by indirect major antigenic protein 1 fragment B (MAP 1-B) ELISA to determine the seroprevalence of Ehrlichia ruminantium and to assess ranch-level risk factors for heartwater. Heartwater-exposed cattle were widespread on the ranch and overall seroprevalence was 50.3% (95% CI, 44.9-55.6), enough to indicate an endemically unstable situation. Multivariate logistic regression modelling was used to identify risk factors associated with seropositivity. Two factors appeared to increase the herd's risk for contracting heartwater. Seroprevalence increased significantly with age (beta = 0.19 per year of age, P < 0.001) and animals carrying ticks of any species were associated with an increased risk of infection with E. ruminantium (Odds ratio, OR = 3.3, P < 0.001). The force of infection based on the age seroprevalence profile was estimated at 18 per 100 cattle year-risk. The current tick control measures on the ranch were associated with a decreased risk of infection with E. ruminantium (OR = 0.25 for no dipping and OR = 0.31 for low dipping, P < 0.001). Six tick species were identified; in order of frequency these were: Ambylomma variegatum 59.9%, Rhipicephalus evertsi evertsi 13.9%, Rhipicephalus pulchellus 12.5%, Hyalomma truncatum 7.03% and Rhipicephalus appendiculatus 6.07%. The least encountered tick was Rhipicephalus simus, which accounted for 0.38%. The cattle seemed well adapted to their environment and capable of resisting the tick burden under this extensive wildlife/livestock grazing and interaction system. 相似文献
8.
Unconditional quantum teleportation 总被引:5,自引:0,他引:5
A Furusawa JL Sorensen SL Braunstein CA Fuchs HJ Kimble ES Polzik 《Science (New York, N.Y.)》1998,282(5389):706-709
Quantum teleportation of optical coherent states was demonstrated experimentally using squeezed-state entanglement. The quantum nature of the achieved teleportation was verified by the experimentally determined fidelity Fexp = 0.58 +/- 0.02, which describes the match between input and output states. A fidelity greater than 0.5 is not possible for coherent states without the use of entanglement. This is the first realization of unconditional quantum teleportation where every state entering the device is actually teleported. 相似文献
9.
Emmanuel Senyael Swai A. Kapaga F. Kivaria D. Tinuga G. Joshua P. Sanka 《Veterinary research communications》2009,33(8):927-936
Despite the widespread prevalence of infection with Peste des petits ruminants virus (PPRV) in goats and sheep industry in
Asia and sub-Saharan Africa, there have been few, if any, structured population-based studies examining the epidemiology of
this infection in Tanzania. In this study, we investigated the seroprevalence, and risk factors, of Peste des petitis ruminants(PPR)
in sheep and goat flocks from seven different geographical administration authorities (Ngorongoro, Monduli, Longido, Karatu,
Mbulu, Siha and Simanjiro) located in Northern Tanzania. Serum samples from 657 and 892 sheep and goats, respectively, corresponding
to 91 sheep/goat flocks and 43 villages were collected. Competitive enzyme linked immunosorbent assay (c-ELISA) was used to
detect the presence of antibodies in the serum against PPRV. Chi-square analysis and multivariable logistic regression model
were used to identify risk factors for PPRV seropositivity. Findings suggested that the sero-positive cases were significantly
higher in goats than in sheep (49.5% versus 39.8%; P = 0.002). The overall seroprevalence of PPRV infection in small ruminants
was 45.8%. Highest seroprevalence (42.6–88.02%) was observed in Mbulu, Siha, Longido, Ngorongoro districts, while antibodies
less than 40% to none were found in serum from Monduli, Karatu and Simanjiro, respectively. These findings confirm natural
transmission of PPRV under field condition for the first time in Tanzania. Results may be correlated with variations in the
sheep and goat husbandry practices within different geographic localities, the uncontrolled movement of animals, the levels
of natural immunity and the sharing of grazing field amongst agro and pastoralists. 相似文献
10.
Karimuribo ED Fitzpatrick JL Bell CE Swai ES Kambarage DM Ogden NH Bryant MJ French NP 《Preventive veterinary medicine》2006,74(1):84-98
In a cross-sectional study of 400 randomly selected smallholder dairy farms in the Tanga and Iringa regions of Tanzania, 14.2% (95% confidence interval (CI)=11.6-17.3) of cows had developed clinical mastitis during the previous year. The point prevalence of subclinical mastitis, defined as a quarter positive by the California Mastitis Test (CMT) or by bacteriological culture, was 46.2% (95% CI=43.6-48.8) and 24.3% (95% CI=22.2-26.6), respectively. In a longitudinal disease study in Iringa, the incidence of clinical mastitis was 31.7 cases per 100 cow-years. A randomised intervention trial indicated that intramammary antibiotics significantly reduced the proportion of bacteriologically positive quarters in the short-term (14 days post-infusion) but teat dipping had no detectable effect on bacteriological infection and CMT positive quarters. Other risk and protective factors were identified from both the cross-sectional and longitudinal included animals with Boran breeding (odds ratio (OR)=3.40, 95% CI=1.00-11.57, P<0.05 for clinical mastitis, and OR=3.51, 95% CI=1.29-9.55, P<0.01 for a CMT positive quarter), while the practice of residual calf suckling was protective for a bacteriologically positive quarter (OR=0.63, 95% CI=0.48-0.81, P相似文献